Add comprehensive full example tutorial and reorganize getting started docs

[oblomov-dev]

Summary

This PR adds a complete end-to-end tutorial demonstrating a realistic abap2UI5 application, reorganizes the getting started documentation structure, and enhances existing docs with clarifications on lifecycle patterns and binding requirements.

Key Changes

New Documentation:

• Added docs/get_started/full_example.md — a comprehensive walkthrough of a complete sales-order management app covering:
  • Selection screen with date range and customer filter
  • Data reading from database
  • Result table display with edit functionality
  • Popup dialog for inline editing
  • Change persistence and table refresh
  • Demonstrates the standard lifecycle pattern with proper state management

Documentation Reorganization:

• Moved sample apps content from dedicated samples.md page into next.md as a discovery section
• Reordered getting started navigation: Introduction → Quickstart → Use Cases → Hello World → Full Example → What's Next?
• Removed standalone samples.md and experimental feature pages (drag_drop.md, smart_control.md)
• Reorganized cookbook sidebar: grouped "Advanced Features" under "Beyond Basics" section with collapsible subsections

Enhanced Existing Documentation:

• Added "Lifecycle Pitfalls" section to lifecycle.md documenting three critical patterns:
  • Bound attributes must be public (not protected/private)
  • View is only sent when view_display() is called
  • check_on_event() fires once per roundtrip
• Updated binding.md with warning about public attribute requirement for binding
• Added "Mapping UI5 XML ↔ ABAP Fluent API" section to definition.md explaining:
  • Naming conventions (snake_case, property mapping)
  • Generic builder for complete UI5 control coverage
  • Recommendation for AI-assisted development
• Added "Jump into the Code" section to hello_world.md documenting Ctrl+F12 source viewer
• Updated cross-references from /get_started/samples to /get_started/next#sample-apps

Notable Implementation Details

• The full example uses dummy data to run without a database, with clear comments showing where real SELECTs and UPDATEs would go
• Demonstrates proper use of public attributes for state management across request roundtrips
• Shows popup lifecycle: opening with popup_display(), closing with popup_destroy(), while main view persists
• Illustrates event dispatching pattern with CASE abap_true and check_on_event()

https://claude.ai/code/session_01Egr9sbJJ944KALJbdahgBG